Pressure sensors are used widely in semiconductor manufacturing to measure pressure and flow of liquid chemicals. An Integrated Flow Controller (IFC), for example, has two such sensors. These sensors often must be isolated from the liquid chemicals to protect the sensors from corrosion and to protect the chemical from contamination. In the past, the sensor isolation has been accomplished by placing a loose fluoropolymer film between the sensors and the chemicals. Over time, exposure to heat and vacuum can cause permanent deformation of the isolator film, which in turn affects sensor performance.
Adhesives have also been used to secure an isolator film to a sensor. However, it has been observed that when the isolator film is exposed to hot deionized water for an extended period of time, bubbles or blisters can form under the isolator film and delamination of the film from the sensor can occur.
There is a continuing need for isolator films to protect sensors from corrosive and high temperature fluids, for example long term exposure to hot water between 85° C. and 100° C.